James Lovelock’s Gloomy Vision

February 13th, 2006 by david

Gloom So what does visionary Lovelock see now? There is no specific, mechanistic scenario for the downfall of civilized man, but rather a gut feeling of approaching catastrophe. Lovelock’s foreboding arises in part from his impression that Gaia is healthiest in the glacial climate state, such as Earth was in 20,000 years ago. The interglacial climate states, such as we inhabit now, he describes as fevers that Gaia must overcome. The origin of this seemingly peculiar perspective is twofold. First, the sun has been warming over geologic time, so the challenge facing Gaia at present is to stay cool. The glacial Gaia is more in control of this challenge than is the interglacial Gaia, so the glacial Gaia must have been the healthier. Second, the CO2 concentration was lower in the glacial atmosphere, which Lovelock interprets as a product of a healthier, more robust biosphere. (I feel compelled to point out here that the carbon isotopic composition of the deep ocean tells us that there was less organic and biosphere carbon during glacial time than there is now. Plants must have struggled to grow in the lower-CO2 atmosphere. It’s not clear to me how the glacial biota was happier than today. Forgive me, I’m small minded, I nitpick.)

Lovelock argues that a cooler land surface retains water better; a warm land surface is either desert or it could be rain forest, which has learned tricks to recycle water efficiently but is very fragile and would collapse with any further warming. A cool surface ocean is biologically productive, while a warm surface ocean is nutrient-limited and therefore a biological desert. Lovelock argues that a robust thriving biosphere is essential for Gaian regulation. (Small-minded me again. The regulation of CO2 by silicate weathering, alluded to above, in theory doesn’t really require trees or life as a central component. The terrestrial biosphere apparently is taking up carbon from the atmosphere, but the real heavy-hitting mechanisms for regulating CO2 on the long term involve dissolution of rocks, chemical reactions that can be influenced by life but do not really require it. A stronger case can be made for life as a necessary part of atmospheric O2 regulation, but it would take millions of years to change O2, so we are not really concerned about asphyxiating in the next century. The critical process is burial of organic matter in ocean sediments, however, not some process associated with forests on land. Despite what you may have read, the rain forests are not actually the lungs of the planet.)

The argument for approaching doom is made by analogy. (Again I feel compelled to editorialize. Argument by analogy is a powerful rhetorical tool, at which Lovelock is a master. Reasoning by analogy however is not a reliable divining rod for scientific discovery. “As above, so below” was a central tenet of the alchemists. We don’t do that anymore.) The analogy is to the failure of natural regulation of a human body, requiring artificial intervention. If the kidneys fail, a doctor has to take over regulation of blood chemistry using dialysis. If the pancreas fails, the patient requires manual regulation of sugar metabolism by insulin injection. It is generally bad news when the doctor tells you that your body’s natural regulation mechanisms are failing, because artificial, technological fixes are typically not as reliable as the natural ones. There is no doubt that mankind is taking over the reins of global geochemical balance. Industrial production of fixed nitrogen for fertilizer now matches the natural rate of nitrogen fixation on the planet. Rates of fossil-fuel CO2 emission dwarf the natural rate of CO2 release in volcanic gases. Lovelock’s conclusion, by analogy, is that the biosphere of the Earth will soon be beset by all manner of unanticipated complications.

This does not seem to me an unreasonable conclusion, I must admit. Consider Biosphere II. This was a sealed greenhouse in the Arizona desert, an attempt to create a managed, self-contained biosphere. A very humbling effort it turned out to be, all in all. Biological control proved to be completely out of reach. Several species of birds were introduced into the system, based on rational design of ecological balance, and all of them went extinct. The only birds that flourished in BII were a local species that invaded the structure while it was under construction that they never managed to eradicate. Ants and cockroaches became so abundant in BII that the biospherians took to sucking them up into vacuum cleaners and feeding them to their domesticated chickens. Geochemically, the oxygen concentration plummeted and nitrous oxide rose, until the structure became uninhabitable.